等离子体活化水中 pH 介导调控实现化学活性高效储存及抗癌效应

The rapid decay of reactive oxygen and nitrogen species (RONS) in plasma-activated water (PAW) limits its biomedical applications. To address this issue, we propose a pH-mediated storage strategy. Our study reveals that prolonging air surface discharge time until the electrode temperature stabilizes at 140 ℃ can induce a dynamic transition from ozone-dominated to nitrogen oxide-dominated regimes, thereby altering RONS concentration trends. During storage, a neutral environment (pH=7) effectively suppresses H₂O₂ decomposition, while an alkaline environment (pH=10) slows NO₂⁻ and ONOO⁻/O₂⁻ decay rates through proton transfer. Acidifying the stored PAW to its initial acidic pH successfully restores its chemical activity, with neutral-stored PAW maintaining optimal anticancer efficacy. By implementing a pH regulation strategy based on “neutral/alkaline storage-acidic activation”, the bioactivity of PAW is preserved long-termly at room temperature. This work elucidates the critical roles of discharge mode transition and pH regulation in determining PAW dosage, providing a theoretical foundation for developing PAW with sustained high activity.